Converter Brands?

[68 C-10 KID]

Sup all.
I'm currently running a Hughes 3500 hd. I'm getting really bad RPM drop as I put it in gear. (500rpm)
So I realize I need to run a bigger converter. I have a 4000 spragless Hughes on the shelf.
I was told the Hughes don't hit hard enough and to much slippage.
So who makes a good converter that's good for our trucks?

My C-10 weight is 3950 and run a 4:10 w/ 28x10.5 Hoosier's and here is some numbers on my sbc 406.

Thanks C-10